In the past, the dock bar has been just an appearance enhancer in operating systems. People have been led to believe that the dock is for those who are more conscious about appearance rather than performance and because of this, they quickly lost interest in it once they got used to it.

In truth, the dock bar can provide you more if you want it to. There are a lot of Dock bar applications available that do just that.

Here are a few Dock Bar applications that are available on the major Operating Systems.

Linux

Gnome Do

Gnome Do is a Quicksilver like application which allows you to search for items present on your Linux Desktop or Web. It also allows you to perform useful actions on the items that are found.
It has a nifty plugin called Docky that it's an excellent dock bar.
Resources
Just open your linux package manager and install it.

Avant Window Navigator

The Avant Window Navigator is an application which tracks open windows and shows the list of the ones which are open. Not only does this increase visual appeal, but it also reduces additional screen space usage.
Resources
Just open your linux package manager and install it.

Cairo Dock

Cairo is different from other dock applications, as it runs a bit faster while remaining visually appealing.
Resources
Just open your linux package manager and install it.

Macintosh

Dockables

This application adds a collection of system events like Restart, Shutdown, and Sleep etc to the dock bar, performing all these actions in just one click.
Resources
Download

SuperDocker

This application lets you tweak your Mac Dock. By tweaking, I mean changing the position of the dock, switching between 2D and 3D, locking items on the dock, etc. SuperDocker can be used to tweak some Finder, Safari and System settings as well, and since these are directly accessible from the dock, it is really useful.
Resources
Download

Dock Dodger

Dock Dodger allows selected applications to run, without having to place dock icons. By dropping the icon onto the Dock Dodger window, that application won’t appear again in the dock bar while running.
Resources
Download

Windows

ObjectDock

It replaces the windows taskbar and shows the applications that are currently being run as icons on the bottom of the screen. The Object dock increases the visual appeal and it brings a welcome change to people who are bored with the Taskbar.
Resources
Download

RocketDock

The RocketDock is similar to ObjectDock, but its appearance can’t be tweaked as much. Even with the limited amount of skins, the RocketDock provides plenty of animations on the dock icons and because of this, it is preferred over ObjectDock by most of the appearance conscious users.
Resources
Download

RK Launcher

RK Launcher is another visually appealing dock application. It allows the user to keep track of newly installed applications by placing a shortcut on the dock. The dock icon can be removed whenever the user wishes.
Resources
Download